1. Field Of The Invention
This invention relates to an improved rolling mill stand construction wherein the work rolls and backup rolls are so configurated so as to permit relative axial displacement of the work rolls with respect to the backup rolls to achieve a desired strip crown configuration or a flat strip.
2. Description Of The Prior Art
Various means for achieving the desired profile of strip such as metal strip being processed in a rolling mill have been known. Included within such known systems and procedures has been the production of flat strip, the production of centrally crowned strip, and the production of strip which is relatively thinner in the center than at the crowned edges.
U.S. Pat. No. 4,162,627 discloses a four high mill wherein cylindrical backup rolls are subjected to axial shifting in order to minimize the bending of the work rolls under rolling pressure and to increase the flatness correcting capacity of roll bending U.S. Pat. Nos. 4,440,012 and 4,519,233 disclose the use f non-symmetrical work rolls which are disposed in relative reverse orientation and are adapted for relative axial displacement so as to move from a position of uniform nip to a position of non-uniform nip.
Japanese patent application No. 54-105155 discloses a pair of non-symmetrical rolls which are reversely oriented with respect to each other and adapted for relative axial shifting.
It has been known to provide rolling mill stands wherein the rolls are moved axially in opposed directions. See generally U.S. Pat. Nos. 3,857,268; 3,943,742 and 4,320,643.
In spite of the foregoing disclosures there remains a need for improved apparatus and methods for obtaining desired crown control in the rolling of strip.